Flat iron



FIG. 1 is a front elevational view of a flat iron, showing my newdesign;

FIG. 2 is rear elevational view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a three quarter perspective view from the rear thereof.

The ornamental design for a flat iron, as shown and described.